1. Field of Invention
The present invention relates to a curing device and a method for curing a frame of a liquid crystal panel, and more particularly to a curing device and a method thereof, which allows an ultraviolet light irradiating to an upper surface and a lower surface of the frame of the liquid crystal panel.
2. Related Art
Compared with a cathode ray tube (CRT), a liquid crystal display panel (LCD panel) has advantages in pact sizes, low power consumption, and low radioactive contamination, such that it has become a mainstream display device. The existing technology which allows liquid crystal molecules to be filled between the substrates includes a vacuum injection method and a one drop fill (ODF) method. In the vacuum injection method, after the two substrates are oppositely disposed, the edges of the two substrates are sealed by a frame (usually comprising a thermal curing material), and then the frame is cured. Next, the liquid crystal molecules are injected into a cavity formed by the frame and the two substrates through an opening based on a capillary principle, and then the opening is closed by a sealant. However, the position offset of the frame is easily occurred during a heating process due to the thermal curing material, and the vacuum injection method is very time consuming, such that the method basically applies to small-size panels.
In recent years, the one drop fill method has been developed. It adopts the material having a photo-curing property to form the frames. In this method, firstly, the frame which has a rectangle shaped seal pattern is formed on a thin film transistor substrate (TFT substrate). Secondly, before the frame is cured, the liquid crystal molecules uniformly drop within the rectangle shaped seal pattern, and the TFT substrate and a color filter substrate are immediately laminated to each other. Then, as shown in FIG. 1, the liquid crystal panel is disposed on a platform 910 of a curing device 900, and the curing device 900 cures the frame by using an illumination unit 920. The illumination unit 920 emits an ultraviolet light 930 to the liquid crystal panel 940 and allows the frame to be cured, such that the frame 950 is adhered to the two substrates to avoid position deviation of the frame 950. Because the ODF method takes a shorter time and a curing quality of the frame is better, most manufacturers adopt the ODF method to fabricate the liquid crystal panels.
However, compared with the vacuum injection method, the above-mentioned ODF method can reduce the liquid crystal injection time. In addition, the frame comprises a material to be cured by the irradiation of ultraviolet light and thermal energy and is directly contacted with the liquid crystals in the liquid crystal panel; however, the ultraviolet light cannot pass through a black matrix on the color filter substrate to irradiate on the frame, and it can only irradiate to the frame through the gaps between electrodes of the TFT substrate to perform a reaction, such that an irradiated area of the frame by the ultraviolet light is less enough which causes an incomplete reaction of a reactive agent of the frame. As a result, an mura appearance is produced around the liquid crystal panel. If the around mura appearance is too serious, it can be seen by naked eyes of users and the display quality of the liquid crystal panel is affected. Thereby, the problems need to be improved.